Abstract

People demonstrate systematic logical failures when reasoning
about conditional statements. In the Wason selection task, a test typically
interpreted as a measure of abstract deductive reasoning, only about 10% of
participants choose the cards prescribed by deductive logic. One possibility is
that people are simply bad at hypothesis testing – biased toward confirming
rather than falsifying abstract conditional rules. A second possibility, however,
is that performance on the task is strongly influenced by pragmatic effects of
linguistic interpretation. In three experiments, we find that manipulating the
instructions to emphasize falsification and that changing the formulation of the
rule to increase the pragmatic salience of the correct choices improves
performance. These results arise because people do not merely decode the logical
content of linguistic expressions. Rather they attempt to understand the
communicative intentions of the individual who produced the expression even in
abstract reasoning tasks.